Hand machine-tool comprising a dust extraction device

ABSTRACT

A hand power tool ( 10 ), in particular with integrated dust removal, that comprises a housing ( 12 ) on which a dust tube ( 22 ) is mounted that is capable of being interconnected with a dust box ( 24 ) by means of its dust inlet connection piece ( 26 ), whereby a side wall ( 27 ) of the dust box ( 24 ) has through holes ( 25 ) that are reached over by a filter in dust-tight fashion, becomes less expensive and more environmentally friendly by the fact that the filter ( 30, 31, 32, 33, 34, 35, 36, 37, 38, 300 ) is formed by a flat sheet composed of a fine-pored material, the surface area of which is increased by means of certain structures.

BACKGROUND OF THE INVENTION

[0001] The invention is based on a hand power tool according to thegeneral description of claim 1.

[0002] A hand power tool is made known in GB 2,343,393 that has a dustbox that enables dust removal with high efficiency and minimal emissionof fine dust.

[0003] The suction of the known hand power tool is created by aventilator rotating with the drive motor of the hand power tool.

[0004] The dust box provided for collecting the sanding/grinding dust isequipped with a fluted filter or a microfilter composed of cellulose.Said filter is sensitive to moisture and cannot be cleaned once itreaches a certain level of contamination, and certainly not in waterand/or solvents. It is therefore not reusable.

[0005] The fluted filter can only be cleaned together with the cover inwhich it is installed. If it can no longer be cleaned, the fluted filtermust be discarded with the cover and replaced with a new cover having acleaned filter

ADVANTAGES OF THE INVENTION

[0006] The hand power tool according to the invention having thefeatures of claim 1 has the advantage that the efficiency of dustremoval at the hand power tool is improved and the emission of finedust, which is low anyway, is reduced even further.

[0007] Due to the fact that the filter sheet is located in the interiorof the dust box on the side closest to the work piece to be worked, thesanding/grinding dust covering said filter sheet increases the filteringeffect without reducing the efficiency of dust removal.

[0008] Due to the fact that the side of the dust box facing the workpiece is designed as a cover inside which the filter sheet is installed,the filter sheet—once the cover is removed—can be cleaned particularlyeasily using a brush or by tapping on it; in particular, it can bewashed conveniently and thoroughly in water or other solvents.

[0009] Due to the fact that the dust box is interconnected with the handpower tool at only one location, i.e., at the dust tube, and istherefore capable of being held in place in captive fashion, furtherfastening means are unnecessary, and the dust box can be detached andremoved from the hand power tool more quickly and conveniently than withpreviously known dust boxes.

[0010] Due to the fact that the filter sheet is fastened to the cover ofthe dust box in detachable fashion, it is particularly easy to clean andreplace with cleaned filter sheets for reuse.

SUMMARY OF THE DRAWINGS

[0011] The invention is described hereinbelow with reference toassociated drawings.

[0012]FIG. 1 is a side sectional detail view of the hand power tool withdust box,

[0013]FIG. 2 is a top view of the hand power tool according to FIG. 1,

[0014]FIG. 3 is a longitudinal sectional detail view of the dust boxwith replaceable filter sheet,

[0015]FIG. 4 is a longitudinal sectional detail view of the dust boxwith non-detachable filter sheet, and

[0016]FIGS. 5 through 11 show various exemplary embodiments of profiledfilter sheets.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017]FIG. 1 shows the side view of a hand power tool 10 designed asoscillating sander. It comprises a housing 12 that has a handle 14 onthe top that extends to the left as viewed in the drawing, and thatcomprises, on its underside, a switching key 15 of anot-further-described switch. With the switching key 15, anot-further-described motor equipped with a motor shaft 20 in theinterior of the housing 12 is capable of being connected to a voltagesource for power supply.

[0018] When the switching key 15 is operated, the motor shaft 20 of themotor rotates and, along with said motor shaft, a ventilator 19 thatsuctions sanding dust collecting under the sanding disc 16 from thenot-shown work piece and blows it through the dust tube 22 into a dustbox 24 via its dust inlet connection piece 26. The dust box 24 iscomposed of four side walls 27 and a bottom 29, and it is capable ofbeing closed in dust-tight fashion with a fitted cover 28. A filtersheet 30 composed of a porous, fine-pored filter material is mounted onthe cover 28 on its side facing the interior of the dust box 24. Thefilter sheet 30 is capable of being detached from the cover 26 innon-destructive fashion, and it can be easily replaced with a new orcleaned filter sheet. The cover 28 is therefore continuously reusable.

[0019] The dust box 24 is interconnected with the hand power tool 10 insuch a fashion that the dust inlet connection piece 26 is pushed ontothe dust tube 22 axially until it stops. The cover 28 of the dust box 24faces downward as viewed in the drawing toward a not-shown work piece.

[0020]FIG. 2 is a top view of the hand power tool 10 with dust box 24according to FIG. 1 in which the locking system 23 for latching the dustbox 24 tightly to the dust tube 22 of the hand power tool 10 in captivefashion is shown particularly clearly. The locking system 23 is composedof not-further-shown pivoted levers that latch onto the dust tube 22when the dust box 24 is joined with the housing 12 of the hand powertool 10, and they hold the dust box 24 captive on the housing 12.

[0021]FIG. 3 is an enlarged longitudinal sectional detail view of thedust box 24, in the cover 28 of which the detachable filter sheet 30 isinstalled. The surface area of the side of said filter sheet that facesthe interior of the dust box 240 is increased by means of rectangulargrooves 40. The grooves 40 form a comb-like profile (FIG. 6).

[0022] After the cover 28 is removed from the dust box 24, the dirtyfilter sheet 30 can be separated non-destructively from the cover 28 andthen cleaned. A replacement filter sheet 30 is then placed on the cover28. Said cover is then clipped onto the side walls 27 via its snap-inconnection. As a result, the filter sheet 30 is held tightly between thecover 28 and the side walls 27 of the dust box 24. The back side of saidfilter sheet bears against the cover 28, and parts of its front sidebear against step-like projections 420 of the side walls 27. It isclamped in captive, dust-tight fashion.

[0023]FIG. 4 is an enlarged longitudinal sectional detail view of a dustbox 240 in which, in contrast to the dust boxes in FIGS. 1 through 3, acaptively-held filter sheet 31 that cannot be detached innon-destructive fashion is installed, and that is snapped in place inpeg spikes 42. The tips of the peg spikes 42 spread apart in the shapeof a vee and hold the filter sheet 31 captive on the cover 280.

[0024]FIG. 5 shows a flat sheet filter 32. FIG. 6 shows a filter sheet300 having a comb profile formed by rectangular grooves 40.

[0025]FIG. 7 shows a filter sheet 34, the cross section of which has atoothlike profile formed by recesses 44 designed in the shape of atruncated cone.

[0026]FIG. 8 shows a filter sheet 35 having a sinusoidal cross-sectionalprofile.

[0027]FIG. 9 shows a filter sheet 36 having vee-shaped grooves 46. FIG.10 shows a filter sheet 37 having stepped, longitudinal grooves 48 thatresult in a Christmas tree-shaped profile and that markedly increase thesurface area of the filter sheet 37.

[0028]FIG. 11 shows a filter sheet 38 with rectangular grooves formed onboth sides in alternating fashion that form a cross-sectional profile ofthe filter sheet 38 that has a meandering shape.

What is claimed is:
 1. A hand power tool (10), in particular withintegrated dust removal, that comprises a housing (12) on which a dusttube (22) is mounted that is capable of being interconnected with a dustbox (24) by means of its dust inlet connection piece (26), whereby aside wall (27) of the dust box (24) has through holes (25) that arereached over by a filter in dust-tight fashion, wherein the filter (30,31, 32, 33, 34, 35, 36, 37, 38, 300) is formed by a flat sheet composedof a fine-pored material, composed of foam in particular, the surfacearea of which is increased by means of uneven structures, i.e.,indentations, in particular.
 2. The hand power tool according to claim1, wherein the filter sheet (30, 31, 32, 33, 34, 35, 36, 37, 38, 300) isinterconnected in replaceable fashion with the dust box (24), i.e., withthe cover (28) in particular.
 3. The hand power tool according to claim2, wherein the filter sheet (30, 31, 32, 33, 34, 35, 36, 37, 38, 300) iscomposed of material that is resistant to water and/or solvents, and itis washable.
 4. The hand power tool according to claim 2, wherein acover (28) is mounted on the dust box (24) on its side facing downwardin the operating position that has through holes (25) and, on the insideof which, the filter sheet (37) is installed.
 5. The hand power toolaccording to one of the preceding claims, wherein the dust box mountsonly on the dust tube (22) of the hand power tool.